The Coriolis Flow Measuring Principle
Introduction to Coriolis Flow Measurement
In this section, we learn about the different substances transported in pipelines and how flow measurement based on the Coriolis principle can be used to measure them.
The Coriolis Principle
- The Coriolis principle is a method of flow measurement that allows for the direct measurement of mass flow.
- The principle was set out by French physicist Gaspard Gustave de Coriolis over 200 years ago.
- A tube is located inside each Coriolis flowmeter. An exciter causes this tube to oscillate constantly.
- If there is no flow, the measuring tube oscillates uniformly. Sensors are located at the inlet and outlet and register this basic oscillation precisely.
Measuring Flow Velocity and Density Simultaneously
- As soon as the fluid starts to flow in the measuring tube, additional twisting is imposed on the oscillation as a result of the liquid’s inertia.
- Due to the Coriolis effect, the inlet and outlet sections of the tube oscillate in different directions at the same time.
- Highly sensitive sensors pick up this change in tube oscillation in terms of time and space. This is known as “phase shift” and is a direct measure of how much liquid or gas is currently flowing through the pipe.
- The higher the flow velocity – and thus total flow – the greater deflection of the oscillating measuring tube.
- To determine density, sensors also register how often (frequency) the measuring tube moves back and forth per second.
- Oscillating frequency is a direct measure of the fluid’s density.
- Both the density and flow are determined simultaneously – but independently – via the tube oscillation.
Advancements in Coriolis Flow Measuring Technology
- Endress+Hauser has continuously revolutionized and perfected Coriolis flow measuring technology in numerous innovative systems.
- This measuring technology is unique as it is the only way multiple process variables – such as mass flow, volume flow, density, temperature, and even viscosity – can be measured simultaneously in pipelines.